Harald,"Who pays these clowns for their GIGO simulations?" - why do you insult those scientists at PIK as "clowns"? They are not clowns, be assured. Is it somehow helpful apart of you being able to vent some frustrations? Likely not. What about looking at their results and how they argue? Maybe they are right? By the way, what means GIGO?

GIGO = garbage in, garbage out.Anyone working in climate modelling knows this very well, Especially those still fit enough to recognise that there's plenty of garbage going in. Concerning the PIK, they are agenda-driven to the core. Anyone who can't see this needs an urgent visit to the eye-doctor. It's not for nothing they lead-authored "The Great Transformation of Society". They've demonstrated time and again that they cannot be trusted. Must we roll out all the tricks and deceptions they've produced in the past? Take a recent Cologne court decision as an example.

Thanks, P. Gosselin, for explaining GIGO. Which "G" went in this time?

I would admit that there were sometimes claims coming out of PIK which I thought of strange; some results were methodically obscure; Rahmstorf received a gag order concerning a journalist, some invented the big transformation, true. But it could nevertheless be that Robinson, Calov and Ganopolsky did a good job.

Would you claim that whatever comes out of PIK is a-priori GIGO?Hm. If YOU would assert such an assessment as legitimate, would you allow ME to claim that whatever comes out of Heartland is GIGO? Maybe a kind of balance of legitimacy of insulting our opponents?

This is my point, they do not provide any meaningful basis for trusting their simulation/model. Backfitting is the backbone of their program, but there is no way to make their results believable, other than waiting 50 000 years.I am sure they are excellent modellers and programmers, but their claim of knowing regional impact, based on a vague 1.6oC global temperature increase is clearly unreasonable. (Although it is easy to prove their model is better than the previous ones)

Their funding sources require them to toe the line. The amount of funding is probably more than Heartland has available.By the way, Hans, Heartland's goal is simply to provide an avenue for countering the "consensus" with scientific discussion; they do not have alternate theories, just the opinion that what is being propogandized as "known science" is not. We all know how incomplete our knowledge of the chaotic system is (clouds).I did not insult the individual programmers, but rather the PIK organization, which in a normal (not post-normal) world would have no reason for existence.

However, in the dissertation, chapter 3 (page 40), one can read sth. else but no references are given:At the same time, the presence of Eemian and older ice in several ice cores indicate that a large portion of the GIS survived the Eemian Interglacial. Moreover, the isotopic composition of Eemian ice from the Greenland summit can be interpreted to show that the height of the summit was not much lower during the Eemian compared to the present day. These data can potentially provide useful constraints for ice sheet models.

I didn't spent attention to that till now. Maybe somebody is more into the Eemian-Greenland topic? I’m i.e. confused about “the isotopic composition of Eemian ice from the Greenland summit can be interpreted to show that the height of the summit was not much lower during the Eemian compared to the present day”

@FreddyThe isotopes are influenced by condensation temperatures which are influenced by climate and (via the lapse rate) the orography of the ice sheet. So in principle each isotope signal is a mixed orography/climate signal.

For the Eem the situation is difficult. There are serious issues with the dating at the bottom (foldings of ice layers etc). Instead of the uncertain interpretation of the isotopes most people just look if there was ice at all during the Eem at the different deep drilling sites. In particular Dye3 in southern Greenland (which was ice covered) puts some limits to ice sheet loss during the Eem.Michiel Helsen here works at a more detailed coupled icesheet/climate model. He addresses about 3 Meter sea level change to Greenland if I remember right. Most of the polemic started with these papershttp://www.sciencemag.org/content/311/5768/1751.abstract

@FredyI just checked the numbers with him. It's a bit more than 2 Meters in about 9000 years (113-122 kyrs BP) with 50cm per 1000 years max. I think there is an agreement that this is on the very low side both for the total volume and for the fastest melting rate.

But it is interesting to see how the message was delivered by Der Spiegel. The time scales were not mentioned in the headline, but at last in the text body of the article.

As to the problem with PIK being bound to alarmism:Yes, I believe that is actually true. As soon as you found a research organisation with such a narrow problem focus, they will always be tempted to prevent the problem from going away.

BUT that does not mean that their arguments are invalid. I believe that, to get back to more rationality in the climate debate, we should not dismiss arguments because of their origin.

The problem with such highly polarised debates is that, finally, all scientific participants seem to be so attached to their opinion that there is nobody left that who would allow himself to be convinced by counter-arguments. In the climate debate, I am afraid, we have reached this point.

I would subscribe to Karl Kuhn's assessment. The challenge is to keep open communication between these "blocks", which means to accept that some of "us" are indeed blockheads, but that not all of "them" are blockheads either (whoever "we" and "they" are).

By the way, I was told about the press release by a stakeholder responsible for coastal defense, and they noticed mainly the time dimension as the significant part of the press release.

Thx @ Georg. Yes I know how the isoptope stuff works - my question relates to the point where these isotopes were taken from. I would need to read more studies about these drillings, depth and location in detail...So it seems that both sides tend to avoid to note the discrepancies of different drillings? At least in my two examples I had bad luck - one study claiming ice-free GIS, the other suggesting almost similar summit for the GIS without refering to each other...

"Rahmstorf received a gag order concerning a journalist, some invented the big transformation, true."

What exactly is the value of this information here? Was Rahmstorf part of this study? And if so, does this "gag order" question his qualities as a scientist? Or do you just want to make sure that we don't forget that Rahmstorf once lost a trial against a journalist?

@Freddy"Yes I know how the isoptope stuff works - my question relates to the point where these isotopes were taken from. "

Well there is probably Eemian ice in all major deep drillings but its not layered and there are foldings and no precise dating.We modelled the isotopic signal during the Eemian and work on the paper (three time slice calculations). But this gets now very technical. If you have questions please contact me.

Werner, I was discussing P. Gosselin contribution about PIK in general, where he/she said: "recent Cologne court decision as an example." Thus, I thought it meaningful to admit that some PIK actors have sometimes acted strangely, but that this would not be good argument to mistrust all results from that institution.

That's what came to my mind. Now everybody is reminded again of Rahmstorf and this case, even though this has absolutely nothing to do with our discussion. (Relativising it - "no reason to mistrust the institution" - doesn't help much. Mentioning it without reason, that's the problem).

Zitat aus dem verlinkten Papier: "The record indicates that warmer temperatures were the norm in the earlier part of the past 4000 years, including century‐long intervals nearly 1°C warmer than the present decade (2001–2010)"

The abstract reads:It is investigated to what extent multiannual accumulation time series from Greenland reflect dynamic and thermodynamic processes and how representative single accumulation series are for the entire ice sheet. Furthermore, it is examined whether accumulation is related to low-level atmospheric temperatures. ... two kinds of regression models are developed which linearly relate multiannual accumulation records to meteorological mean fields. Seven ice cores from north to central Greenland and the NCEP Reanalysis data are used for the period from 1948 to 1992. ... One group of regression models distinguishes between dynamic and thermodynamic atmospheric effects. ... For six of the ice cores, these regression models describe more than 56% of the variability of the smoothed accumulation series, confirming that they represent to a large extent atmospheric states. Multiannual accumulation variability is found to dominantly represent circulation variability. However, the circulation fieldsthat are linked with accumulation show marked differences among the cores concerning the represented seasons, areas, and structures. Thus local accumulation generallyrepresents only regional-scale climate features, which are probably to a great extent influenced by orography. Furthermore, regression models using only 700 hPa temperature as predictor show that a general linear relationship between accumulation and temperature does not exist over this 45-year time interval. ... it is not reasonable to describe accumulation by means of temperature in mass balance models for the Greenland ice sheet in decadal timescales.

"To study the long-term response of the GIS to rising temperaturesmore directly, we used an intermediate complexity, regionalclimate model14 coupled to an ice-sheet model15 (see Methods).This new approach has been shown to reproduce the regionalclimate well compared to observations14 and, most importantly,it explicitly incorporates the albedo and elevation feedbacks thatare important for proper simulation of the long timescale responseof the GIS to climate change."

@HansIt's allways the surface mass balance that is meant in the abstract?That would exclude all melting/calving in coastal areas which might be more directly linked to (summer) temperatures (ie total mass ballance is better related than surface mass balance)?

I have a question regarding the ratio of Arctic warming, global average temperature and the sea levels:

I understand that the estimates of Arctic warming and sea level rise are based on the past interglacials, especially the Eemian. Then the high north latitudes warmed up a lot due to increase of summer solar insolation by about 13 %. The tropics apparently even cooled compared to present and some studies (e.g. Hansen & Sato) estimate GAT was few tenths of a degree higher than today, max one degree. Hence predictions of radical seal level rises if GAT rises.

However, today the solar forcing is less and CO2 will provide the warming. However, CO2 produces a much more uniform warming pattern and is especially effective in the tropics. Hence GAT will rise much faster than during the Eemian.

So, the Eemian Greenland ice sheet melt and sea level rise was produced by solar warming that was most pronounced in the high NH latitudes in the summer. For the same reason, GAT did not increase much.

Now we have CO2 warming that is also warming the tropics so GAT will rise faster. However, we will not have more solar warming in the north.

One paper argued that 45% of GIS melt during the Eemian was due solar insolation and associated feedbacks, 55% temperature rise effects.

On the basis of this, isn't the use of Eemian GAT rise/GIS melt ratio to predict modern GIS melt and sea level rise a fallacy?

"Pirate said... 32 "I have a question regarding the ratio of Arctic warming, global average temperature and the sea levels: On the basis of this, isn't the use of Eemian GAT rise/GIS melt ratio to predict modern GIS melt and sea level rise a fallacy?"

I do not really know, but I think there is a general solution. The saw tooth like oscillations of ~8° Cel. (There must be a big heat source anywhere which creates this heat current on the Earth). That shows that the temperature is increased in a few single years, with relaxing times of ~50ky. The grade of relaxing time is also confirmed by Prof. G. Patzelt from his measurement in the Alps. This means that the high level after ~10ky to 20ky after the boost is still present. One effect of the temperature boost was melting of the polar ice with the result of an increasing sea level of ~120 meter. The rate of increasing sea level has decreased until today to a low value. Some 6ky ago the Doggerbank in the North Sea was without water and the sea level is now 30m over ground. Looking to the variations of the still slowly increasing sea level, there are some oscillations with frequencies of ~1/1000 years, as we know from the temperature cycle warm peaks of the time ~1100 AD to 2000 AD and the cold peaks in the LIA. Whatever the reason is for this temperature oscillation, it is clear that it modulates the decreasing long term temperature relaxation of ~50ky with the result of temporary increasing sea levels also for some 400 years until to day or for some 200 years ahead. As a second effect of higher ocean temperatures an increase of the sea level happened from the density property of water, which is higher at higher temperatures (>4°Cel.). Doing some math on it, one can separate this effect from the sea level data. The perspective looks like a saturation in the increasing rate of the sea level for some 10ky – 30ky ahead but with the 1/1000 y-1 oscillations of some cm pp. There are hints from the frequency spectra from the saw tooth oscillations giving the geometry of the oscillator.

Sustainable use of KLIMAZWIEBEL

The participants of KLIMAZWIEBEL are made of a diverse group of people interested in the climate issue; among them people, who consider the man-made climate change explanation as true, and others, who consider this explanation false. We have scientists and lay people; natural scientists and social scientists. People with different cultural and professional backgrounds. This is a unique resource for a relevant and inspiring discussion. This resource needs sustainable management by everybody. Therefore we ask to pay attention to these rules:

1. We do not want to see insults, ad hominem comments, lengthy tirades, ongoing repetitions, forms of disrespect to opponents. Also lengthy presentation of amateur-theories are not welcomed. When violating these rules, postings will be deleted.2. Please limit your contributions to the issues of the different threads.3. Please give your name or use an alias - comments from "anonymous" should be avoided.4. When you feel yourself provoked, please restrain from ranting; instead try to delay your response for a couple of hours, when your anger has evaporated somewhat.5. If you wan to submit a posting (begin a new thread), send it to either Eduardo Zorita or Hans von Storch - we publish it within short time. But please, only articles related to climate science and climate policy.6. Use whatever language you want. But maybe not a language which is rarely understood in Hamburg.

Deutsche Welle collects your questions about climate

The German broadcaster Deutsche Welle collects your questions via email, youtube, facebook and twitter, which will be the answer by an expert.